This year, we published five articles on mismatch repair (MMR) in yeast. In one study, we found that the histone protein H2A.Z regulates genome stability, and we propose that this may result from affects on MMR activity. In another study, we found that mismatches generated by DNA polymerase alpha are repaid by a mismatch repair process involving the Rad27 nuclease. The other three studies investigate the role of MMR in correcting errors across the whole nuclear genome. Two of these studies investigated correction of base-base mismatches that result in base substitutions and correction of mismatches that result in insertions and deletions, all made by polymerase active site variants of DNA polymerases alpha, delta and epsilon. The third study investigates MMR of errors made by these polymerases when the cell encodes exonuclease-deficient variants of DNA polymerases delta and epsilon. All these studies are relevant to the role of MMR in evolution of species and in development of cancer.